The investment worth after 42 years is $115200, so option 2 is correct
Solution:
Given, an investment of $1,800 doubles in value every 7 years. We have to find how much is the investment worth after 42 years from the given set of options.
[tex]\begin{array}{l}{\text { Now, after } 7 \text { years } \rightarrow 1800 \times 2=3600} \\\\ {\text { After } 14 \text { years } \rightarrow 3600 \times 2=7200} \\\\ {\text { After } 21 \text { years } \rightarrow 7200 \times 2=14400} \\\\ {\text { After } 28 \text { years } \rightarrow 14400 \times 2=28800} \\\\ {\text { After } 35 \text { years } \rightarrow 28800 \times 2=57600} \\\\ {\text { After } 42 \text { years } \rightarrow 57600 \times 2=115200}\end{array}[/tex]
Hence, the investment worth after 42 years is $115200, so option 2 is correct.
